It is well known that when assembling a motor vehicle, particularly one with a transverse engine, it is necessary to provide a flexible coupling between the exhaust manifold which is fixed to the engine, and the exhaust pipe which is fixed to the bodywork and which supports the silencer.
In order to take up the relative movement between the manifold and the exhaust pipe, and to prevent leaks, one of the lengths of pipe terminates in a convex spherical mating surface, either fashioned from the end of the tube itself or formed by an annular gasket, which co-operates with a complementary surface on the other length of pipe. In order to hold the parts together in such a case, the exhaust manifold and the exhaust pipe include respective connecting flanges associated with each length of pipe and joined together by means of bolts, each of which is surrounded by a compression spring to ensure a leak-proof coupling.
Upon relative movement of the two lengths of exhaust pipe, the two spherical surfaces rub against each other generating extremely unpleasant vibrations. The level of these vibrations has already been reduced by providing a special type of gasket between the facing ends of the lengths of exhaust pipe. However, it has not yet been possible to completely suppress the vibrations generated by the various parts of the coupling rubbing together during use.
Although the production of vibrations cannot be totally suppressed, one object of the invention is to minimize their effects.